In Plain Sight - Season 5 Episode 4

A man, who sells pharmaceuticals to doctors, witnesses one of his clients do something illegal so he testifies and enters WITSEC along with his family. His daughter who plays lacrosse is told she has to stop, because she was so good that they could be discovered and her whole family could be placed in jeopardy. A few months in, Mary and Marshall learn the man is seeing another woman and they learn that she's also his wife. She's allowed into WITSEC but she has to be told about her husband's other family and vice versa, and that's when things get messed up. And his daughter disappears.